This disclosure relates to the field of pressure control systems used in connection with wellbores drilled through subsurface formations. More particularly, the disclosure relates to apparatus used with well pressure control systems that enables multiple well intervention operations to be performed without the need to move personnel close to the well pressure control system.
U.S. Pat. Nos. 9,670,745 and 9,644,443 issued to Johansen et al. disclose various example embodiments of a wellhead pressure control apparatus. Disclosed embodiments include a cam lock design with a secondary lock, in which the pressure control apparatus replaces connections done conventionally either by hammering, torqueing, or with a quick union nut, all of which require the interaction of a human operator to perform these operations. The disclosed embodiments include a wellhead pressure control fitting comprising a generally tubular Pressure Control Equipment (PCE) adapter having first and second adapter ends wherein the first adapter end is configured to mate with pressure control equipment.
In some embodiments disclosed in the foregoing patents, the second adapter end provides an annular first adapter rib, a generally tubular pressure control assembly having first and second assembly ends and a longitudinal centerline, the centerline defining axial displacement parallel to the centerline and radial displacement perpendicular to the centerline. The first assembly end providing a first assembly end interior, the second assembly end configured to mate with a wellhead, the first assembly end interior providing a PCE receptacle for receiving the second adapter end, the second adapter end and the PCE receptacle further each providing cooperating abutment surfaces, the cooperating abutment surfaces forming a pressure seal between the second adapter end and the PCE receptacle when the second adapter end is compressively received into the PCE receptacle, the first assembly end interior further providing a lower wedge assembly, the lower wedge assembly including a plurality of lower wedges, each lower wedge having first and second opposing lower wedge sides, each first lower wedge side providing protruding top and bottom lower wedge ribs, a generally hollow lower wedge receptacle, the lower wedge receptacle further providing a plurality of shaped lower wedge receptacle recesses formed in an interior thereof, one lower wedge receptacle recess for each lower wedge, the lower wedge receptacle further having first and second opposing lower wedge receptacle sides in which the lower wedge receptacle recesses define the first lower wedge receptacle side, and wherein each lower wedge is received into a corresponding lower wedge receptacle recess so that the first lower wedge receptacle side and the second lower wedge sides provide opposing sloped lower wedge surfaces, wherein axial displacement of the lower wedge receptacle relative to the lower wedges causes corresponding radial displacement of the lower wedges, and wherein, as the second adapter end enters the PCE receptacle and engages the cooperating abutment surfaces, axial displacement of the lower wedge receptacle relative to the lower wedges c
In such embodiments as disclosed in the foregoing referenced patents, a crane operator may place pressure control equipment (PCE) directly onto the wellhead using the pressure control apparatus's highly visible entry guide. The crane operator may then proceed to actuate the pressure control apparatus and secure the pressure control equipment in embodiments where the crane is equipped with the apparatus's remote controls. In some embodiments, a second operator may operate the pressure control apparatus remotely while the crane holds the pressure control equipment in the entry guide.
Embodiments of the pressure control apparatus disclosed in the foregoing patents also provide a “night cap” option to cap the well if there will be multiple operations. Consistent with conventional practice in the field, the apparatus includes a night cap option, available separately, for sealing off the wellhead while the PCE has been temporarily removed, such as at the end of the day. Embodiments including the night cap enable the apparatus to remain connected to the wellhead, and wellhead pressure to be retained, in periods when PCE is temporarily removed.
In some well operations, one or more balls may be dropped to actuate devices within the wellbore, for example, fracture zone isolation seals.